Thermal Vacuum Environment Research Articles

Stabilization of lithium-drifted silicon surface-barrier detectors

Abstract A simple fabrication technique has been found which yields lithium-drifted silicon surface-barrier detectors which have a low leakage current and which exhibit stable electrical and α-particle characteristics under conditions of prolonged aging and repeated exposure to thermal-vacuum environments. The detectors will operate at a temperature of 65°C and high vacuum for several days with no evidence of noise instability. The operating characteristics of such detectors have been studied over a period of several months. These studies included measurements of their electrical and α-particle characteristics taken before, during, and after thermal-vacuum testing at 65°C and additional testing at 50°C. Degradation in electrical and α-particle characteristics resulting from such testing and aging was found to be negligible over a period of approximately four months. The measurements at 50°C and 65°C indicate that the fractional change in the mean energy per ion pair is approximately −1.3 × 10 −4 /°C over the temperature range from room temperature to 65°C. The results of these studies are reported.

Thermal-vacuum behavior of lithium-drifted silicon detectors

The potential advantages of lithium-drifted silicon detectors compared with conventional silicon surface-barrier detectors under conditions of a thermal-vacuum environment are discussed. Both surface-barrier and n-i-p lithium-drifted detectors have been fabricated which will operate at elevated temperatures and high vacuum for extended periods of time with no evidence of noise instability. The operating characteristics of several litjium-drifted silicon detectors have been studied before, during and after environmental testing to investigate the effects of such testing on detector properties. The results of these studies are reported.

Optimum Focusing of Space Camera Systems

After the success of the Ranger 7 television mission, an exhaustive study was undertaken to determine whether the performance of the succeeding Ranger payloads could be made to surpass that of Ranger 7. In this paper, (1) the effect of thermal-vacuum environment on camera focus is found to be substantial and a method of compensation for this effect is discussed; (2) the focusing methods used on Ranger 7 are evaluated; and (3) the improvements in focusing based on (1) and (2) above are discussed.

Performance of silicon materials in thermal-vacuum environments: C. L. Whipple and E. G. Curtindale, Trans. 10 Nat. Vac. Symp., New York, 1963, 63–68

Performance of silicon materials in thermal-vacuum environments: C. L. Whipple and E. G. Curtindale, Trans. 10 Nat. Vac. Symp., New York, 1963, 63–68

Performance of silicon materials in thermal-vacuum environments

Performance of silicon materials in thermal-vacuum environments